Below are some suggested Source Types for TMG based on my interpretation of the models given in
QuickSheet: Citing Online Historical Resources by Elizabeth Shown Mills. I
believe that these faithfully reproduce citations that follow the principals
given in the QuickSheet models. There could be other interpretations using
different Source Elements and/or Source Element Groups which would be equally
valid.

These Source Templates use the standard TMG Source Element Groups and the standard TMG Source Elements
except for five Custom Source Elements. Anyone using these Source Types should
add these five Source Elements to their project before using the Custom Source
Types containing any of these five Custom Source Elements. They (and the Source
Element Group to which each is assigned) are:Custom Source ElementSource Element Group Site
Owner Editor
Issue Record Number
Access
Date Second Date
Site
Name Subject
Newsletter
Title Title

I have created an empty project called ONLINE containing a dummy person and
the above Source Types. You may download the backup of ONLINE,
and then File=>Restore the project. After
you have restored it, you can then merge the ONLINE project
with your own project (make a backup of your project first). This will place the
Custom Source Types shown above in a data set in your project. You may then be merge
that data set
with your own data sets as desired. The backup here was created using TMG v6.12, so
you must have that version (or later) to use it.